Colbert’s appearance will be closed to the press. Former President Bill Clinton will also be delivering private remarks to the caucus on Friday.

Colbert will be speaking to a group that his sister, Elizabeth Colbert-Busch, is seeking to join. Colbert-Busch recently launched a bid for the Democratic nomination in the special election to replace Rep. Sen. Tim Scott (R-SC) (R-S.C.) in the House.